The objective of this program is to establish stable and sensitive viral microarray assays for public health laboratory, hospital-based clinical laboratory and point-of-care-use to enable differential diagnosis of infection by select NIAID priority agents, agents that may cause signs and symptoms that may mimic those due to infection with select agents, and influenza viruses. We propose four specific aims: Aim 1, Establish, implement and validate bioinformatics tools and databases to support microarray design and updates;Aim 2, Create specialized arrays for detection and speciation of select viral agents and influenza viruses;Aim 3, Establish array protocols for use with clinical materials;and Aim 4, Implement assays in public health laboratories in the New York State Department of Health, the Centers for Disease Control, Hong Kong University, the Robert Koch Institute, and the Public Health Agency of Canada. Features that will enhance the probability of programmatic success include: (1) expertise of applicants in clinical microbiology, bioinformatics, and molecular diagnostics;(2) a sensitive and stable microarray platform;(3) access to proprietary databases of select agent and influenza virus sequences;(4) a comprehensive inventory of extracts from infected cultured cells, naturally and experimentally infected animals, and human victims of infection with select viral agents or influenza viruses;(5) partnership in a dedicated international surveillance network wherein clinical samples can be shared for assay optimization, validation, and implementation to support global public health;and (6) commercial partners with expertise in manufacture, licensure, distribution of diagnostic reagents.